1. Technical Field
The present invention relates to an illuminating device including a light emitting element, a method of manufacturing the same, and an illuminating device. In particular, the present invention relates to a ring-shaped illuminating device for illuminating an object to be imaged when acquiring an image.
2. Related Art
In the field of FA (Factory Automation) and the like, various types of image processing techniques are being used. Typically, an image processing technique for recognizing characters printed on an object to be examined, and examining for the presence of scratches on a surface of the object to be examined and the like, based on the image data obtained by imaging the object to be examined, is being widely put to practical use.
When performing various types of measurement processes on the object to be examined using such image processing technique, the image representing the object to be examined needs to be appropriately acquired. For this reason, an illuminating device for illuminating the object to be examined is often arranged to ensure appropriate illumination at the time of imaging. As the illuminating device described above, an illuminating device using a light emitting element (LED: Light Emitting Diode) having low power consumption and long lifespan is put to practical use.
In the illuminating device using such a light emitting element, a configuration using a so-called chip LED is adopted in place of a conventional shell type LED.
For example, Japanese Unexamined Patent Publication No. 2002-184209 discloses an LED illuminating device including a flexible printed circuit substrate held in a predetermined stereoscopic shape, and a large number of light emitting diode elements directly attached to the flexible printed circuit substrate according to a predetermined pattern.
Japanese Unexamined Patent Publication No. 2002-83506 discloses an illuminating device in which a light emitting unit with a flexible substrate and a large number of light emitting diodes mounted on one surface of the flexible substrate is arranged in a case. In such an illuminating device, the configuration of arranging in the case with the other surface of the flexible substrate not mounted with the light emitting diode and the inner surface of a main body facing each other is adopted.
Japanese Unexamined Patent Publication No. 2000-269549 discloses an illuminating device capable of achieving uniform illumination effect over a wide area with respect to the object to be illuminated having an elongate shape.
In the ring-shaped illuminating device disclosed in Japanese Unexamined Patent Publication No. 2008-139708, a plurality of LED columns are concentrically arranged and a plurality of optical members are concentrically arranged in correspondence with respective LED columns so that illumination modes on a workpiece by the respective LED columns differ from each other, and respective additional optical members are arranged to realize an integrated structure. A single device thus can support a plurality of types of objective lenses and workpieces.
In an LED illuminating device disclosed in Japanese Unexamined Patent Publication No. 2009-146841, positioning pins arranged on a flat base portion are inserted to through-holes formed in a flat LED substrate mounted with a plurality of LEDs and positioning pin insertion holes formed in an integrated lens holder for holing a plurality of lenses to position the lens holder with respect to the LED substrate. The individual lens thus can be positioned with respect to each of the plurality of LEDs.